The present invention relates to a device for cleaning aquarium windows, in particular the inside thereof, comprising an interior element, which is to be placed on the inside of the aquarium window, as well as an exterior element, which is to be placed on the outside of the aquarium window, which interior and exterior elements attract each other under the influence of magnetic force, so that movement of the exterior element along the aquarium window causes the interior element to follow this movement. The present invention furthermore relates to a method for cleaning aquarium windows, in particular the inside thereof, using two elements fitted with magnets.
A device and method of this kind for cleaning the inside of aquarium windows, using magnets, is known from British patent application No. 2,105,977. The apparatus disclosed therein comprises an interior device having a permanent magnetic field and a pair of cleaning faces substantially perpendicular to each other, and an exterior device having a permanent magnetic field for manipulating the interior device. When apparatus of this kind is used, the interior device is placed on the inside of the aquarium window, after which the exterior device is placed on the outside on the aquarium window, with the magnetic forces causing the two devices to xe2x80x9cstickxe2x80x9d to the aquarium window. When the exterior device is moved along the aquarium window, the interior device will follow the movements of the exterior device and thus clean the inside of the aquarium window. A drawback of such apparatus is the fact that when the magnetic contact is broken, the interior device will sink to the bottom of the aquarium, so that it will have to be removed therefrom by means of a scoop net or by hand. Another important drawback is the fact that when such a method of cleaning aquarium windows is used, the interior device must be pressed against the inside of the aquarium window by hand, whilst at the same moment the exterior device must be placed against the outside of the aquarium window, which makes it necessary for the upper side of the window to be readily and easily accessible. In many aquariums a cover plate is present on the upper side of the aquarium, however, so that the placing of the interior device is not an easy operation, which considerably increases the risk of the interior device suddenly becoming detached and thus sinking to the bottom.
The use of magnetic forces for cleaning windows, using a window cleaner having magnets, is also known from Netherlands patent application 8700802. The window cleaner known from said publication is especially suitable for cleaning windows of a building on the outside, which windows cannot be reached from ground level or from an upper floor. The problem that has been observed by the present applicant, that is, the sinking to the bottom of an element suitable for cleaning windows, is not known therefrom, and accordingly a window cleaner as disclosed in said publication does not provide the solution for the problem observed by the present applicant.
U.S. Pat. No. 5,515,570 relates to a manually operated window wiper, which document does not describe the problem observed by the present applicant, viz. the sinking to the bottom of the element suitable for cleaning windows. U.S. Pat. No. 4,977,637 furthermore discloses a magnetic window cleaning apparatus wherein a suction cup is connected via a hose to the window cleaning. apparatus so as to prevent the latter from becoming detached from the window to be cleaned.
Although devices for cleaning aquarium windows are known from U.S. Pat. No. 4,571,766, European patent application No. 0 527 580 and U.S. Pat. No. 5,601,322, such devices are not fitted with one or more magnets.
The object of the present invention is to overcome the above problems.
Another object of the present invention is to provide a method which makes it possible to clean the inside of aquarium windows quickly and efficiently in a simple manner.
Another object of the present invention is to provide a device for cleaning aquarium windows, which device can be produced by means of a simple production method.
The device as referred to in the introduction is according to the present invention characterized in that the interior element is so constructed that, once the magnetic force has been removed, the interior element will remain afloat on the liquid medium that is present in the aquarium.
Since the element to be placed on the inside of the aquarium, which element can be considered to be the interior element hereafter, is designed to have buoyancy, said element will not sink to the bottom upon removal of the magnetic force. When for example the magnetic force between the interior element and the element to be placed on the outside of the aquarium window, which element can be considered to be the exterior element hereafter, is removed, the interior element will rise to the surface of the liquid, after which the floating interior element can be drawn towards the aquarium window through manipulation of the exterior element, so that a close contact between the exterior and interior elements is established again. Since liquid flows occur inside the aquarium, there will always be a moment when the interior element floating on the liquid is located within the magnetic field of the element present on the outside of the aquarium window, so that the contact between the two elements can be reestablished.
In a special embodiment of the present invention it is preferable to design the device so that it comprises an air chamber which is to give the interior element buoyancy.
The presence of air in the element to be placed on the inside of the aquarium window ensures that the interior element will rise to the liquid surface upon removal of the magnetic force rather than sink to the bottom.
In another preferred embodiment of the present invention it is preferable with a view to obtaining buoyancy that the element to be placed on the inside of the aquarium window includes a material which has a density lower than that of the liquid medium which is present in the aquarium.
Suitable materials are for example plastic, foam, wood and the like, whereby it is of course important in view of the buoyancy thereof that the density of the eventual element to be placed on the inside of the aquarium window is lower than the density of the liquid medium which is present in the aquarium, so that the buoyancy is ensured. When such a material is used, a leak in the air chamber of the interior element, for example, which allows water to penetrate into the interior element, will not cause the interior element to sink to the bottom.
It is in particular preferable that both the element to be placed on the inside of the aquarium window and the element to be placed on the outside of the aquarium window are fitted with one or more magnets.
By fitting both elements with magnets, a strong connection between the two elements is ensured, which connection is in particular very important when very thick aquarium windows are to be cleaned. A powerful magnetic field is also required when the interior element is to clean the aquarium windows near the bottom of the aquarium, because the force exerted on the interior element is considerably larger there than near the liquid surface. Moreover, by using magnets in both elements the magnetic contact will not easily be broken, which is very important when cleaning round certain obstacles, such as pumps, water plants, decorative stones.
In a special embodiment of the present invention it is desirable for the interior element to include a material which can be attracted by a magnetic field rather than being fitted with the magnets as described above.
The interior element of such an embodiment may for example include an iron plate or any other material which is capable of being attracted by magnetic forces. A considerable saving in weight can be achieved by using such a material instead of magnets. In addition, a cost reduction can be achieved in this manner.
In order to obtain a good cleaning effect while using the element to be placed on the inside of the aquarium window, it is in particular preferable for said element to comprise a rough surface on the side parallel to the aquarium window.
As a result of the provision of a rough surface, the aquarium window, on which dirt is present, can easily be cleaned by moving the rough surface of the interior element along said window. A rough surface can for example be obtained by providing the interior element with a scale-like or grid-like structure. Such a structure can be obtained by means of an injection moulding process, using a mould of simple design.
In order to prevent the outside of the aquarium window from becoming scratched, the element to be placed on the outside of the aquarium window preferably has a smooth surface on the side parallel to the aquarium window. Such a smooth surface of the exterior element can for example be obtained by using a felt-like material.
The present invention furthermore relates to a method for cleaning aquarium windows, in particular the inside thereof, using an interior element, which is to be placed on the inside of the aquarium window, and an exterior element, which is to be placed on the outside of the aquarium window, which elements attract each other under the influence of magnetic force, wherein the exterior element is moved along the aquarium window and the interior element follows said movement under the influence of the magnetic force, which method is characterized in that the device as described above is used.